Dynamometers have been used extensively for measuring speed and torque from power sources such as engines or motors that have a rotating output shaft. Dynamometers, alternatively, have also been used to determine the torque and power required to operate a device commonly powered by an engine or motor.
In the area of automobile testing, dynamometers have been used to measure the output from engines as well as the requirements of driven components, such as transmissions and differentials. One common testing configuration is shown in U.S. Pat. No. 3,330,153 to Perna Jr. wherein an engine, via a transmission, drives a differential. A first dynamometer is coupled to an output half axle extending from a first side of the differential. Similarly, a second dynamometer is coupled to an output half axle extending from a second, opposite, side of the dynamometer.
In operation, each dynamometer reads the speed and torque from the respective rotating differential output shafts while the engine is operating. Additionally, the dynamometers can selectively be loaded with resistance to simulate varying driving conditions, such as driving around a curve.
As dynamometers are generally costly items, flexibility in the use of a dynamometer for multiple tests is desired. As described above, a single dynamometer can have a loads applied thereto to simulate many different driving conditions. Additionally, dynamometers are made that can act both as a driving dynamometer (simulating a driving device: motor or engine) and an absorption dynamometer (simulating a driven device). Even more flexibility is desired, however.
In vehicle testing, dynamometers used are relatively large (typically heavier than one ton) and, thus, are placed in a single position, movable at most linearly to and/or away from a shaft that the output of the dynamometer is coupled to; that shaft extending from the device being tested. However, within a single vehicle or vehicle configuration, it may be desirable to test vehicle components singularly, or that are located in significantly different positions, such as the differential alone or in combination with a transverse mount vehicle transmission, each testing scenario requiring a different configuration.
What is desired is a testing setup using multiple dynamometers (driving and absorption) where the position of the dynamometers can be easily and significantly changed.